/Engine/Plugins/MovieScene/MovieRenderPipeline/Source/MovieRenderPipelineCore/Public/MoviePipelineSurfaceReader.h
Issues a command to the GPU to copy the given SourceSurfaceSample to our local ReadbackTexture for this surface.
void ResolveSampleToReadbackTexture_RenderThread ( const FTexture2DRHIRef & SourceSurfaceSample )